Source/Drain Materials for Ge nMOS Devices: Phosphorus Activation in Epitaxial Si, Ge, Ge 1−x Sn x and Si y Ge 1−x−y Sn x

  • Vohra A
  • Makkonen I
  • Pourtois G
  • et al.
10Citations
Citations of this article
10Readers
Mendeley users who have this article in their library.

Abstract

This paper benchmarks various epitaxial growth schemes based on n -type group-IV materials as viable source/drain candidates for Ge nMOS devices. Si:P grown at low temperature on Ge, gives an active carrier concentration as high as 3.5 × 10 20  cm −3 and a contact resistivity down to 7.5 × 10 −9 Ω.cm 2 . However, Si:P growth is highly defective due to large lattice mismatch between Si and Ge. Within the material stacks assessed, one option for Ge nMOS source/drain stressors would be to stack Si:P, deposited at contact level, on top of a selectively grown n -Si y Ge 1− x − y Sn x at source/drain level, in line with the concept of Si passivation of n -Ge surfaces to achieve low contact resistivities as reported in literature (Martens et al. 2011 Appl. Phys. Lett. , 98 , 013 504). The saturation in active carrier concentration with increasing P (or As)-doping is the major bottleneck in achieving low contact resistivities for as-grown Ge or Si y Ge 1− x − y Sn x . We focus on understanding various dopant deactivation mechanisms in P-doped Ge and Ge 1− x Sn x alloys. First principles simulation results suggest that P deactivation in Ge and Ge 1− x Sn x can be explained both by P-clustering and donor-vacancy complexes. Positron annihilation spectroscopy analysis, suggests that dopant deactivation in P-doped Ge and Ge 1− x Sn x is primarily due to the formation of P n -V and Sn m P n -V clusters.

Cite

CITATION STYLE

APA

Vohra, A., Makkonen, I., Pourtois, G., Slotte, J., Porret, C., Rosseel, E., … Vandervorst, W. (2020). Source/Drain Materials for Ge nMOS Devices: Phosphorus Activation in Epitaxial Si, Ge, Ge 1−x Sn x and Si y Ge 1−x−y Sn x. ECS Journal of Solid State Science and Technology, 9(4), 044010. https://doi.org/10.1149/2162-8777/ab8d91

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free